Electric heater



mames Sept. 20, i949. B, J. GRAYCAREK ELECTRIC HEATER Filed Dec. 15,1947 Patented Sept. 20, 1949 ELECTRIC HEATER Benjamin J. Graycarek,Manitowoc, Wis., assignor of one-half to George W. Noll, Manitowoc,

Wis.

Application December 15, 1947, Serial No. 791,914

(Cl. 21B-39) 4 Claims.

This invention relates to electric heaters and be used for otherpurposes.

Objects of this invention are to provide a novel form of electric heaterwhich is arranged to be attached to the blower side of :a vacuum cleaneror to some other source of -air under a slight pressure and which is.arranged to first preheat the air by passing the Iair through thecentral portion of the porcelain body of an electric heater andthereafter diverting the air rearwardly and passing it over the heatingwires of the heater so that the air is super heated, and thereafterdirected forwardly from the device.

Further objects are to provides. heater so that it is impossible forsparks or burning dust particles to be discharged from the heater, thearrangement being such that t-he air that passes over the heated wiresis caused to travel rearwardly and thereafter is deflected forwardly,thus giving a long travel for the air and causing any burning dust or`other sparks to be driven against the rear portion lof the heater andthus extinguished.

Further objects are to provide a novel form of electric heater-which isof very Asimple construction and which may be cheaply made and mosteasily assembled.

An embodiment of the invention isy shown in the accompanying drawings,in which- Figure 1 is .a vertical sectional view through the majorportion of the heater.

Figure 2 is a iront end View partly broken away.

Referring to the drawings, it will .be seen that the heater comprises abody portion l which is generally circular :and which may be formed ofplastic, if so desired, or of metal. In the event it is formed ofplastic it must be of a type which will not soften under heat. Ifdesired, the front portion or discharge end 2 of the heater may beslightly converged or contracted. The rear portion 3 of the heater isprovided with an annular groove 4 which, in reality, constitutes la halftorus and serves to direct the :air lforwardly as will be apparent asthe description proceeds. This rear portion is provided with a reducedinwardly projecting extension 5 which is provided with a plurality ofspaced pins 6 adapted to be received in bayonet slots 'l formed in theporcelain cylinder 8 4of the electric heater. This construction allowsthe ready insertion or removal the cylindrical porcelain member 8 whichis provided with spiral grooves that receive the heating, spirallycoiled wire 9. It is to be noted that the wire 9 projects outwardly aconsiderable distance from the porcelain cylinder 8 so that the airpassing rearwardly actually passes between `the successive convolutonsof the wire and thus is thoroughly heated. The :air is also preheated byvpassing forwardly from the inlet opening IU of the heater. This inletopening I0 is supplied with air under a slight pressure from anysuitable source as from the blower end Il of a vacuum cleaner.

The main .body portion of the heater is provided with an inner shell orcylindrical member I2 which is integral with the outer member I and maybe joined thereto by a plurality of struts I3. This inner shell I 2 islocated between the porcelain shell 8 Iof the heater and the outer bodyportion I. The outer end of the shell I2 is provided with a plurality ofpins I4 which are received in bayonet slots I5 formed in ia front capmember I6. This Vfront cap member is preferably formed of metal Ias iti-s subjected to a considerable amount of heat from the impinging heatedair. This front cap I6 is provided with an annular groove I1 which formsa half torus and which has a central cusp I8. It serves Ito direct theoncoming air passing outwardly from the porcelain tube or shell 8rearwardly so that it crosses fthe heating wires or heating elements 9as previously described. The heating wires or heating elements may beconnected to a plurality of binding posts or bolts I9 from which theoutwardly extending leads or conductors 20 may pass. It is preferable toprovide a pair of insulating tubes 2l of suitable material `which arescrew threaded as indicated at 22 into the shell I2. These insulatingtubes 2l are provided `with notches 23 adjacent the bolts I9 so as toreceive the conductors or leads 2B. When the leads 20 are connected tothe binding posts or bolts I9 they are drawn up snugly and thus preventrotation of the porcelain cylinder 8 and thus prevent detachment of thecylinder 8 from the reduced extension 5 of the body portion.

It is a very easy matter to assemble this device for it is apparent thatthe heating element, consisting of the porcelain cylinder 8 and thewires 9, is iirst inserted from the front of the device and the bayonetslots 1 `are interlock-ed with the pin 5. Thereafter the conductors 20are clamped to the bolts or binding posts I9 and are threaded throughthe tubes 2| which are screwed into the of the heating unit. The heatingunit comprises shell l2 as stated. After this the front cap I6 3 o1'front air de'ector is locked to the shell I2 by the interengagement ofthe bayonet slots I and the pins I4 as described hereinabove.

If desired, the body portion may have integrally or otherwise formedclamping means indicated generally by the reference character 24 so thatit may be clamped to any suitable support.

It is to be distinctly understood that the main body portion consistingof the shells I and 2 and the rear portion 3 and the struts or spacersI3 may be formed of any suitable material whether it be metal or plasticor other suitable material. The front cap I6 likewise can be formed ofany suitable material, though it is preferable to form this member ofmetal.

It will be seen that a novel form of electric heater has been providedby this invention which is of simple construction and which is veryeffective and highly efficient in heating the air as the air is rstpreheated and thereafter super heated by rst being passed through theheating unit and thereafter being passed around the heating unit so thata high degree of heat transfer from the heating unit to the air isobtained.

It is to be understood that this device can be used as a hair drier oras a space or room heater and can be made in any size desired.

It is to be understood that while a cylindrical body portion andcylindrical shells have been illustrated, that nevertheless theexpression cylindrical is not to be interpreted in a limiting sense butis intended to cover any tubular shape whatsoever whether it be trulycircular in cross section or whether it be polygonal, or whether it havesome other shape.

Although this invention has been described in considerable detail, it isto be understood that such description is intended as illustrativerather than limiting, as the invention may be variously embodied and isto be interpreted as claimed.

I claim:

1. An electric heater for heating a large volume, low pressure stream ofair comprising a body portion having an outer shell and an inner shellspaced from said outer shell to provide a discharge passageway forheated air, an electric heater having a central tubular body portion anda heating element on the outer side of said tubular body portion, saidelectric heater being located within said inner shell and spaced fromsaid inner shell,

d means for directlng a current of air successively forwardly throughsaid central tubular body portion, rearwardly over and in direct contactwith the heating element between the heater and the inner shell, andforwardly and outwardly between said inner and outer shells.

.2. An electric heater comprising a body portion having outer and innerspaced shells, an electric heater within said inner shell, and means fordirecting a current of air forwardly through said electric heater topreheat the air, rearwardly over the outer side of said electric heaterin direct contact therewith to super heat the air, and forwardly betweensaid inner and outer spaced shells to discharge the heated air through azone separated off from said electric heater.

3. In a device of the class described for heating a large volume, lowpressure stream of air, a hollow cylindrical heater, means for directinga current of air forwardly through said heater, a half torus-shapeddeflector located in front of said heater for directing the current ofair rearwardly over the outer side of said heater, and means fordirecting the current of air away from said heater.

4. An electric heater comprising a cylindrical body portion, anjnnercylindrical member supported from said body portion and spaced from theinner wall thereof to provide an annular air discharge passageway, saidbody portion being open at the iront and having a closed rear portionprovided with an air inlet opening for directing a current of airinwardly, a hollow electric heater detachably supported from the rear ofsaid body portion with therhollow interior of said heater in alignmentwith said inlet opening and located within said inner cylindrical memberand spaced therefrom, and a circular cap member detachably attached tothe front of said inner cylindrical member and having an annularrecessed portion'for receiving the heated current of air from theinterior of said heater and directing such heated air rearwardly betweensaid heater and said inner cylindrical member to super heat said air,the rear part of said body portion having an annular recessed portionfor receiving the air from between said inner cylindrical member andsaid heater and arranged to direct the super heated air outwardlythrough the discharge passageway between said inner cylindrical memberand said body portion.

BENJAMIN J. GRAYCAREK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,252,614 Pieper et al Jan. 8,1918 1,949,658 Remseth et al Mar. 6, 1934 2,028,095 Tully et al Jan. 14,1936 2,042,264. Levenhagen May 26, 1936

